package com.atguigu.gulimall.product.service.impl;

import lombok.AllArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    CategoryDao categoryDao;
    
    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //baseMapper这里是因为继承了ServiceImpl，ServiceImpl要给两个泛型，给了CategoryDao
        //ServiceImpl里的baseMapper就是泛型指定的类型
        //查出所有分类
        List<CategoryEntity> categoryEntities = baseMapper.selectList(null);
        //组装成父子的树形结构
        List<CategoryEntity> level1Menus =categoryEntities.stream().filter((categoryEntity)->{
            //父分类的id，如果等于0说明是一个一级分类
            return categoryEntity.getParentCid() ==0;
        }).map((menu)->{
            menu.setChildren(getChildrens(menu,categoryEntities));
            return menu;
        }).sorted((menu1,menu2)->{
            return menu1.getSort() - menu2.getSort();
        }).collect(Collectors.toList());
        return level1Menus;
    }

    /**
     *
     * @param root 当前菜单
     * @param all 所有菜单
     * @return
     * 递归查找所有菜单的子菜单
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            //父ID等于指定这个菜单的Id那么当前菜单就是他的子菜单
            return categoryEntity.getParentCid() == root.getCatId();
        })//为每一个当前菜单找到子菜单
          .map(categoryEntity -> {
              //找到子菜单  如果有子菜单就会递归查
            categoryEntity.setChildren(getChildrens(categoryEntity,all));
            return categoryEntity;
        })//排序
          .sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        })//收集到所有的菜单toList
          .collect(Collectors.toList());
        return children;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO 检查当前删除菜单是否被其他地方引用
        //逻辑删除
        baseMapper.deleteBatchIds(asList);
    }
}